Unable to create new service: ChromeDriverService

Question

I have globally installed Selenium Standalone:

npm install selenium-standalone -g
selenium-standalone install --singleDriverInstall=chrome

I have also bastardised the code from this page into this dotnet core / XUnit test:

using System.Threading;
using System;
using Xunit;
using OpenQA.Selenium;
using OpenQA.Selenium.Remote;
using OpenQA.Selenium.Chrome;
using System.Diagnostics;

namespace XunitTestLib.Unit
{
    public class BasicBrowserTest : IDisposable
    {
        public Process _process;
        public IWebDriver Browser { get; }

        public BasicBrowserTest()
        {
            _process = new Process()
            {
                StartInfo = new ProcessStartInfo
                {
                    FileName = "selenium-standalone",
                    Arguments = "start --drivers=chrome",
                    UseShellExecute = true
                }
            };
            _process.Start();

            var options = new ChromeOptions();
            // options.AddArgument("--headless");
            options.AddArgument("--disable-gpu");
            options.AddArgument("--no-sandbox");
            options.AddArgument("--ignore-certificate-errors");
            options.AddArgument("--allow-insecure-localhost");
            options.AddArgument("--acceptInsecureCerts=true");
            options.AddArgument("--proxy-server='direct://'");
            options.AddArgument("--proxy-bypass-list=*");
            options.SetLoggingPreference(OpenQA.Selenium.LogType.Browser, LogLevel.All);

            Thread.Sleep(4000);
            Browser = new RemoteWebDriver(options);
        }

        public void Dispose()
        {
            Browser.Dispose();
            _process.CloseMainWindow();
        }
    }
}

I am trying to start up selenium-standalone with ChromeDriver so that I can driver the browser to perform browser testing.

I am not hosting my own web application - this is only test run tests against a site which is already running.

The Sleep is to allow selenium to start up in the shell process.

However, I get this output when run with dotnet test --filter DisplayName="Homepage":

[xUnit.net 00:00:04.88]     Homepage [FAIL]
Failed   Homepage
Error Message:
 System.InvalidOperationException : Unable to create new service: ChromeDriverService
Build info: version: '3.141.0', revision: '2ecb7d9a', time: '2018-10-31T20:22:52'
System info: host: 'horacepc', ip: '191.191.191.1', os.name: 'Windows 10', os.arch: 'amd64', os.version: '10.0', java.version: '1.8.0_201'
Driver info: driver.version: unknown (SessionNotCreated)
Stack Trace:
   at OpenQA.Selenium.Remote.RemoteWebDriver.UnpackAndThrowOnError(Response errorResponse)
   at OpenQA.Selenium.Remote.RemoteWebDriver.Execute(String driverCommandToExecute, Dictionary`2 parameters)
   at OpenQA.Selenium.Remote.RemoteWebDriver.StartSession(ICapabilities desiredCapabilities)
   at OpenQA.Selenium.Remote.RemoteWebDriver..ctor(ICommandExecutor commandExecutor, ICapabilities desiredCapabilities)
   at OpenQA.Selenium.Remote.RemoteWebDriver..ctor(Uri remoteAddress, ICapabilities desiredCapabilities, TimeSpan commandTimeout)
   at OpenQA.Selenium.Remote.RemoteWebDriver..ctor(Uri remoteAddress, ICapabilities desiredCapabilities)
   at OpenQA.Selenium.Remote.RemoteWebDriver..ctor(ICapabilities desiredCapabilities)
   at OpenQA.Selenium.Remote.RemoteWebDriver..ctor(DriverOptions options)
   at XunitTestLib.Unit.BasicBrowserTest..ctor() in C:\git\core\XunitTestLib\Unit\BasicBrowserTest.cs:line 46

Total tests: 1. Passed: 0. Failed: 1. Skipped: 0.
Test Run Failed.

The line the error is indicating is this line: Browser = new RemoteWebDriver(options);

My understanding is that the ChromeDriver is attempting to connect to selenium via an HTTP connection, but is failing to start/initialise.

I don't understand why it is failing.

Answer 1

The answer turns out to be including the required list of NuGet packages. The blog post from Scott Hanselman documents these:

dotnet add package "Selenium.Support"
dotnet add package "Selenium.WebDriver"

This third package is required for the code in the post above to work:

dotnet add package "Selenium.WebDriver.ChromeDrive"

Answer 2

This doesn't answer your question about using selenium-standalone specifically, but in my experience, it may be unnecessary if you just want to run them on your local machine.

Instead, if you download Chromedriver from http://chromedriver.chromium.org/downloads and then instead of using new Process you can do:

var driverPath = "C:\\MyWebDrivers";
var driverExecutableFileName = "chromedriver.exe";
var options = <whateveryouhadabove>;

using (var service = ChromeDriverService.CreateDefaultService(driverPath, driverExecutableFileName))
{
    using (var driver = new RemoteWebDriver(service.ServiceUrl, options.ToCapabilities()))
    {
        // control chrome here!
    }
}

Behind the scenes, ChromeDriverService.CreateDefaultService will be creating a "Web Driver" compatible interface via chromedriver.exe.